Method of combatting weeds



METHOD OF COMBATTING WEEDS Harry Tilles, El Cerrito, and Joe Antognini, Mountain View, Calif., assignors to Staulter Chemical Company, a corporation of Delaware No Drawing. Filed Feb. 13, 1957, Ser. No. 639,852

4 Claims. (Cl. 71-23) This invention relates to certain aryl, both substituted and unsubsttiuted, thiolcarbamates as herbicides. More specifically, the invention relates to compounds of the general formula R It and/ or R H phenyl CH p-ohlorophenyl C H p-tolyl nG H p-ethoxphenyl 1-O H ZA-dimethylphenyl i-O4H9 IlO4Hv allyl The novel compounds of the present invention may be made in accordance with the following non-limiting examples. Code numbers have been assigned to each compound and are used throughout the balance of the application.

Example I (R-2097) 10 g. (0.058 mole) of phenyl ohlorothiolformate was dissolved in 125 cc. of ethyl ether and the solution was cooled to 5-l0 C. in an ice bath. 13.4 g. (0.119 mole) of 40% dimethylamine solution in water was slowly added, keeping the reaction mixture cool by means of the ice bath. The ether solution was then separated from the aqueous phase, dried over anhydrous magnesium sulfate and the ether was then evaporated on the steam bath with the aid of a current of air. There Was obtained as a residue, 10.3 g. of phenyl N,N-dimethylthiolcarbarnate, 12 1.541.

Example II (ll-2098) 10 g, (0.058 mole) of phenyl chlorothio-lformate was dissolved in 125 cc. of ethyl ether and the solution was cooled to 5-10 C. in an ice bath. 8.7 g. (0.119 mole) of diethylamine was slowly added, keeping the reaction mixture cool by means of the ice bath. The reaction mixture was then filtered from the solid amine hydrochloride and the ether filtrate was concentrated on a steam bath with the aid of a current of air. There was obtained as a residue, 10.8 g. of phenyl N,N-diethylthiolcarbamate,

Example III (It-2099.)

When the general procedure of Example II was repeated except that 12.0 g. (0.119 mole) of di-n propylamine and 10 g. 0.058 mole) of phenyl chlorothiolformate were 2,977,209 Patented Mar. 28, 1961 employed, there was obtained 14.2 g. of phenyl N,N-di-npropylthiolcarhamate, 11 1.5418.

Example lV (R-2101) When the general procedure of Example II was repeated except that 12.0 g. (0.119 mole) of di-isopropylamine and 10 g. (0.058 mole) of phenyl chlorothiolfor-mate were employed, there was obtained 13.5 g. of phenyl N,N- d-i-isopropylthiolcarbamate, M.P. 98.5 102.5 C.

Example V (R-2l03) When the general procedure of Example H was repeated except that 15.3 g. (0.119 mole) of di-isobutylamine and 10 g. (0.058 mole) of phenyl chlorothiolformate were employed, there was obtained 15.1 g. of phenyl N,N-diisobutylthiolcarbamate, n 1.5310.

Example VI (R-2l04) When the general procedure of Example II was repeated except that 10.4 g. 0.119 mole) of N-methylbutylamine and 10 g. (0.058 mole) of phenyl chlorothiolformate were employed, there was obtained 12.9 g. of phenyl N- methyl-N-n-butylthiolcarbamate, n 1.5517.

Example VII (R-2105) When the general procedure of Example II was repeated except that 12.0 g. (0.119 mole) of N-ethyhn-butylamine and 10 g. 0.05 8 mole) of phenyl chlorothiolformate were employed, there was obtained 13.9 g. of phenyl N-ethyl- N-n-butylthiolcarbamate, 11 1.5443.

Example VIII (R-2107) Example X (ii-2109) VJlren the general procedure of Example I I was repeated except that 8.7 g. 0.119 mole) of n-butylarnine and 10 g. (0.058 mole) of phenyl chlorothiolformate were employed, there was obtained 11.9 g. of phenyl N-n-butylthiolcarbamate, 11 1.5547.

Example XI (R-ZIIO) When the general procedure of Example II was repeated except that 11.5 g. (0.119 mole) of diallylamine and 10 I g. (0.058 mole) of phenyl chlorothiolfonnate were employed, there was obtained 13.6 g. of phenyl N,N-dially1- thiolcarbam-ate, 11 1.5675.

Example XII (R-21I1) When the general procedure of Example II was repeated except that 6.8 g. (0.119 mole) of allylamine and 10 g. (0.058 mole) of phenyl chlorothiolformate were employed, there was obtained 11.1 g. of phenyl N-allylthiolcarbamate, n 1.5828.

Example XIII la-2112 When the general procedure of Example II was repeated except that 4.5 g. (0.099 mole) of anhydrous dimethylamine and 10 g. (0.048 mole) of p-chlorophenyl chlorothiolformate were employed, there was obtained 9.9 g. of p-chlorophenyl N,N-dimethylthiolcarbamate, M.P. 7

Example XIV (R-2169) carbamyl chloride was added over an interval of 5 minutes. The mixture was refluxed for an additional 10 minutes and was then cooled to room temperature. The reaction mixture was then washed with 1-100 cc. portion of 2% sodium hydroxide solution and 1-100 cc. portion of water. The xylene solution was then dried over anhydrous magnesium sulfate and the solvent was evaporated .OD. the steam bath with the aid of a current of air. There was obtained as a residue 18.7 g. of p-tolyl N,N- dimethylthiolcarbamate, n 1.5766,

Example XV (R-2170) When the general procedure of Example XIV was repeated except that sodium dispersion equivalent to 1.1 g. (0.048 mole) of sodium, 7.8 g. (0.051 mole) of p-ethoxybenzenethiol and 5.0 g. (0.046 mole) of dimethyl carbamyl chloride were employed, there was obtained 8.6 g. of p-ethoxyphenyl N,N-dimethylthiolcarbamate, M.P.

4 per acre. The pots were placed in a greenhouse and watered at suitable intervals and the germination and growth of the seeds was compared with similarly planted seeds to which no herbicide was added. In each case, germination was reported on the scale of -100%, while growth was reported on a scale of 0-10, based on the seeds which germinated. Thus, 100-10 indicates normal germination and normal growth.

The following data were obtained:

Oats Cucumbers Radish Compound Percent Growth Percent Growth Percent Growth Germ. Germ. Germ.

The above tests were then repeated using application rates of 10 and 40 pounds per acre with the following 85-865 results:

Rate/ Peas Corn Radish Rye Cucumber Compound Age,

Ge. Gr. Ge. Gr Ge. Gr Ge. Gr. Ge Gr 10 100 10 100 9 100 10 0 50 7 R s .2 as .t .tt 2 7 0 5 5 6 3 i 5o 3 100 7 100 7 0 s R 2099 10 100 10 100 10 100 10 75 4 100 10 40 100 10 100 8 100 10 5 0+ 100 10 R 21O1 10 100 10 100 10 100 10 75 8 100 10 40 100 10 100 10 100 10 75 0+ 100 10 10 100 6 100 10 100 10 25 2 75 10 40 10 0+ 100 6 100 10 0 75 10 10 100 10 100 10 100 10 25 6 100 10 40 100 8 100 6 100 10 0 60 9 R4110 10 100 10 100 10 100 10 25 1 100 10 40 100 8 100 8 100 10 0 50 7 R 2u2 10 100 s 100 s 100 10 75 s 100 s 40 50 3 75 4 100 7 0 50 5 1 Germination. 9 Growth.

Example XVI (R-2171) When the general procedure of Example XIV was repeated except that sodium dispersion equivalent to 2.4 g. (0.105 mole) of sodium, 15.2 g. (0.110 mole) of 2,4-dimethylbenzenethiol and 10.8 g. (0.100 mole) of dimethyl carbamyl chloride were employed, there was obtained 19.6 g. of 2,4-dimethylphenyl N,N-dimethylthiolcarbamate, n 1.5707.

Example XVII (R-2172) lowing typical tests show. Some of the compounds are quite selective in their action and can be used to eradicate or control one type of plant, while another type of plant is relatively unafiected.

In making the following tests, seeds were planted in 3" pots and shortly thereafter the compound under test was applied to the pots as a drench at the rate of 365 pounds The compounds of the present invention may be used as preemergence or postemergence herbicides and may be applied in a variety of ways at various concentrations. They may be combined with suitable carriers and applied as dusts, sprays or drenches. The amount applied will depend on the nature of the seeds or plants to be controlled and the rate of application may vary from 1 to 500 pounds per acre. One particularly advantageous way of applying the compounds is as a narrow band along a row crop, straddling the row.

We claim:

1. The method of oombatting weeds comprising applying a phytotoxic amount to the soil of a compound selected from the group consisting of phenyl N,N-dimethylthiolcarbamate, phenyl N,n-butylthiocarbamate, and phenyl N-allylthiolcarbamate.

2. The method of claim 1 wherein the compound is phenyl N-n-butylthiolcarbamate.

3. The method of claim 1 wherein the compound is phenyl N-allylthioloarbamate.

4. The method of claim 1 wherein the compound is phenyl N,N-dimethyl thiolcarbamate.

(References on following page) 5 3 References Cited in the file of this patent 2,776,196 Gysin et a1. Ian. 1, 1957 UNITED STATES PATENTS 2,776,197 Gysin et a ---Ja:l1- 195 2,060,733 Hunt et a1 Nov. 10, 1936 2363399 Hams 1958 2,160,880 Loane et a1. June 6, 1939 5 2,268,382 Claud et a1. Dec. 30, 1941 OTHER REFERENCES 2,631,935 Baumganner Mar, 17, 1953 Thompson et al. in Chemical Abstracts, Vol. 41, cols. 2,650,876 Stewart Sept. 1, 1953 3902 to 3913 (3905(g) applied), 1947. 2,723,989 Harman Nov. 15, 1955 Templeman et *al. in Chemical Abstracts, vol. 41, col.

2,744,898 Harman et a1. May 8, 1956 10 7039 to 7040, 1947. 

1. THE METHOD OF COMBATTING WEEDS COMPRISING APPLYING A PHYTOTOXIC AMOUNT TO THE SOIL OF A COMPOUND SELECTED FROM THE GROUP CONSIISTIING OF PHENYL N,N-DIMETHYLTHIOLCARBAMATE, PHENYL N,N-BUTALTHIOCARBAMATE, AND PHENYL N-ALLYLTHIOLCARBAMATE. 